Place-holder for prerequisites.yml

We need this file to be in place to add an additional step
to the CI jobs.

In subsequent PRs, we can add steps into this file.

playbooks/prerequisites.yml

@@ -0,0 +1,7 @@
+---
+- name: Place holder for prerequisites
+  hosts: localhost
+  gather_facts: false
+  tasks:
+  - name: Debug placeholder
+    debug: msg="Prerequisites ran."